The invention pertains to a drive system for a crop processing device and for a crop transport device of a harvesting machine, which system can be operated at least in a first operational mode and in a second operational mode. In the first operational mode, the crop processing device is driven by a first drive power supplying device and at least part of the drive power is made available to the crop transport device by a second drive power supplying device so that the crop transport device supplies crop to the crop processing device and the crop processing device is driven in the second operational mode by the second drive power supplying device.
U.S. Pat. No. 6,052,978 describes a drive system for the feed rollers and the chopper drum of a forage harvester. During the harvesting operation the chopper drum is mechanically driven. The mechanical drive is also connected to the sun gear of a planetary transmission. The ring gear of the planetary transmission is driven by a hydraulic motor and the planet gear carriers are connected to the feed rollers. As a result, the speed of the feed rollers and the associated cut length can be infinitely adjusted by varying the speed of the hydraulic motor. The planetary transmission can be blocked in itself in order to pass through only the torque of the hydraulic motor to the feed rollers or to the chopper drum. As a result, the chopper drum can be slid backwards or forwards. However, the known drive system has the disadvantage that the feed rollers are permanently driven by the hydraulic motor, that is, even during sharpening.
In other conventional forage harvesters, a switchable transmission is used for the drive of the feed rollers and the driven elements of the crop take-up device. This transmission is brought manually into a neutral position before sharpening, which causes great complexity, since the driver must climb out of his cab and go to the transmission that is located in the vicinity of the crop feed conduit.
The invention has the basic problem of making available an improved drive system in which the disadvantages cited above are not present.
According to the present invention, there is provided an improved drive arrangement for the crop feed and processing elements of a harvesting machine.
The invention is relative to a drive system of a crop processing device and of a crop feed or transport device of a harvesting machine that can be operated at least in a first and in a second operational mode. In the first operational mode, a first drive power supplying device, as a rule an internal combustion engine, drives the crop processing device directly or indirectly, that is, via intercalated mechanical transmissions or other power transfer devices such as hydrostatic transmissions. At least part of the drive power is made available to the crop transport device feeding crop to the crop processing device in the first operational mode by a second drive power supplying device. In the second operational mode that is used, e.g., for sharpening the crop processing device with a changed speed or direction of rotation, the second drive power supplying device drives the crop processing device. In order to prevent a rotation of the crop transport device in the second operational mode, the invention suggests that a stop device block a rotation of the crop transport device in the second operational mode.
In this manner, the second drive power supplying device is used for two tasks, namely, in the first operational mode for driving the crop transport device, and in the second operational mode for driving the crop processing device; however, an undesired rotation of the crop processing device is avoided in the second operational mode.
The second drive power supplying device preferably comprises a separate motor. A hydraulic motor is preferably used, although an electric motor can also be used. An embodiment of a motor with changeable initial speed makes it possible to adjust the transport speed of the transport device that influences the cut length achieved in a forage harvester.
It is also basically conceivable that the motor of the second drive power supplying device produce the entire drive power for the transport device. However, in order to be able to use a less powerful, and thus smaller and more economical motor, it is preferred to allow the drive power to be made available to the transport device at least partially also from the first drive power supplying device A planetary transmission or another superposed transmission can be used thereby that is coupled to the motor and, in the first operational mode, to the first drive power supplying device. The speed of the crop transport device can be adjusted with the planetary transmission in the first operational mode by varying the speed of the motor. It is meaningful in such an embodiment to block the planetary transmission in itself in the second operational mode, e.g., by establishing a rigid connection between the sun gear and the planet-gear carrier in order to pass through the drive power of the motor to the crop processing device, that for its part is separate from the first drive power supplying device. However, a separate drive train can also be used in the second operational mode between the motor and the crop processing device.
There is the possibility of not only stopping the crop transport device in the second operational mode, but also of separating it from the second drive power supplying device. The stop device can, as is known in cutoff couplings of metal detectors, separate the drive first, and shortly thereafter in time, stop the crop transport device. In a preferred embodiment, a clutch coupling is used that can be activated in the first operational mode by a first element controlled by a metal detector. Furthermore, a second element is provided that activates the clutch coupling in the second operational mode. The first and/or second element(s) is/are preferably also used to stop the transport device. To this end, conventional stop latches can be used that engage cog wheels that are cogged in a sawtoothed manner and are arranged on a shaft that drives the transport device.
In the second operational mode, even the driven elements of a crop pickup device can be stopped by putting a shifting transmission associated with them in neutral.
Note that the stop device and the other controllable elements cited are, as a rule, not brought individually and manually by the operator of the harvesting machine by switches into their positions associated with the particular operational modes, but rather, are regulated electronically or electromechanically by a control connected, for its part, to an input device preferably located in a cab. The operator selects the first, second or any other operational mode desired in the input device and the control brings about the described activation of the controllable elements.